Sunday, December 5, 2010

Science Lesson #5: Density

The density lab was one of my favorite labs to teach when I was a TA. The lab exercises were simple: One bowl of water with different sized blocks all made out of the same type of wood. With all the blocks floating in the water, students were asked to examine the % above water and % below water. They found out it was the same percentage regardless of the size of the block, therefore all the blocks have the same density. Simple and effective!

Density might seems like a dry subject for a kid's show, but it's such an integral concept in science. It's hard to move on to larger topics without first laying the foundation. Here are some ideas of what to touch on in this episode.

- Density formula: density = mass per unit volume
- What is mass? Emphasize that it is different than weight- What is volume? Describe simply
- Density explains why things sink or float in water
- How density changes when materials change phase (solid, liquid, gas)
- Archimedes story about the bath water rising - water displacement is associated with density
- Talk about the unique property of water: that the solid is less dense than the liquid, is why ice floats
- Comparing density of other substances: rocks, metals, gases (some sink b/c heavier than air)

I want this episode to introduce the geography of the imaginary world of the HMS Unknown. The episode starts out with the Crew watching a news report that the residents of a peninsula attached to the continent of New Kittyland (go with me on this) are concerned about recent earthquakes. They think that since their peninsula is attached to the continent by a small strip of land that it could break free in a large earthquake and sink into the sea. The residents of New Kittyland are woefully uninformed about how density works, therefore the crew of the HMS Unknown must travel to this distant land to calm their fears. The Captain and Crew teach Marisol about density on the way there.

I'm thinking this episode also needs some interpersonal drama. I hesitate to put a lot of romance stuff in because it is still a kid's show, but even the Muppets had some romance! We find out that Rodger is sweet on Sophia who totally does not reciprocate his affection. In fact, all this amorous gestures tend to confuse Sophia more than titillate her. I like that idea. It could make for some very silly gags.